Manchester City have lived in the shadow of their bigger and wealthier neighbours for longer than they will care to remember, but that all changed yesterday with the arrival of the United Arab Emirates royal family and a multi-billionaire described as the Donald Trump of Abu Dhabi.

This morning City find themselves not only the richest club in Manchester but perhaps the world. The announcement yesterday that Thaksin Shinawatra, the former prime minister of Thailand, had sold the club to Abu Dhabi United Group (Adug) is expected to be followed by the biggest injection of cash into a football club since Roman Abramovich changed the face of the English game with his £600m-plus investment in Chelsea.

Abramovich's wealth saw Chelsea overtake Manchester United and Real Madrid on the global rich list. Now City, a club that has been synonymous with glorious failure, can claim the title as their own, boasting the kind of wealth that led one source to say of the deal: "Imagine Chelsea, then times it by at least 10."

The club wasted little time in flexing their financial muscle yesterday, tabling almost £100m in bids for new players and clinching Real Madrid's Brazilian forward Robinho for a British record £32.5m when he had seemed destined for Chelsea.

Adug is fronted by Sulaiman al-Fahim, a 31-year-old businessman, property mogul and reality-television show host who is ranked 16th in Arabian Business Magazine's list of 100 most powerful Arabs, with a personal wealth said to be 10 times that of Abramovich.

Last night he insisted he had not put up the money himself but was a figurehead for members of the UAE's royal family, whose riches are even greater, and that the aim was to establish City among the world's elite clubs.

"Our goal is very simple - to make Manchester City the biggest club in the Premier League," said Fahim.

Fahim is chief executive of Hydra Properties, a company set up only two years ago but which has already signed more than £1bn worth of contracts in Abu Dhabi, Dubai, Mexico and around the world. Fahim, a flamboyant character, is regularly seen in Hollywood and was recently pictured with Leonardo di Caprio.

Like Trump, he hosts his own reality show, The Hydra Executives, an Arabic version of The Apprentice, albeit on a rather more extravagant scale than the Sir Alan Sugar version. The prize: $1m (£550,000) to invest in property. The takeover has cost around £210m and clears all City's outstanding debts. Thaksin had run into financial problems after the Thai courts froze £800m of his assets; he may never recover that after fleeing his home country last month to avoid multimillion-pound corruption charges. Thaksin was deposed as prime minister in a 2006 coup and has been described as a "human rights abuser of the worst kind" by Amnesty International

His trial is taking place in his absence and the authorities in Thailand are investigating whether he can be extradited from London, where he is living in exile. In the meantime, he will relinquish his chairman's role at City but stay on as honorary president, with a minor stake.

The new owners do not have the same baggage although, for the time being, there is mystery as to precisely which members of the UAE royal family are involved.

Fahim said they had been contacted three weeks ago by a "mutual friend," having previously considered investing in three other Premier League clubs.

"We've received a lot of offers and have been made aware of the possibility of 10%, 20% or 25% investments in Newcastle United, Liverpool and Arsenal. But there have been no real discussions and those possibilities have never gone anywhere.

"The only team and offer that grabbed my mind was Manchester City."

The talks concluded in Dubai on Sunday night when Thaksin signed off his stake. City had managed to keep the news out of the public domain although the club's executive chairman, Garry Cook, had said recently that Thaksin was looking to bring in investment from "some very wealthy friends".

Cook predicted great things for City. "Can we be as big, or bigger, than Manchester United? Yes. Can we win the Premier League? Yes. Can we win the Champions League? Yes. It might take 10 years, maybe even longer. But we will." The new owners believe it will be even quicker. "We don't have a lot of time," said Fahim. "The money is not a worry for my board."

He said the new owners would take an active role in the club and would attend City's next game. That will be against Chelsea on September 13, when City's supporters are planning to celebrate the new-found wealth by wearing Arab headgear.